| 摘要 |
Fabrics are made from continuous filament or short fibre yarns, either alone or mixed with other fibres or filaments, which have been made by converting animal hide material by means of swelling agents and if desired mechanical treatment into a highly swollen slippery paste, the latter being extruded under pressures of the order of 100 atmospheres to produce filaments which are dried and thereafter are rendered waterproof, for example, by treatment with tanning agents or pyroligneous acid. The paste in which the natural fibres of the hide material are maintained, should contain not more than 20 per cent of dry substance preferably 6--12 per cent; and the necessary swelling may be effected in acid or alkaline media, or in an alkaline medium followed by an acid medium, according to the selected conditions at values of pH over 12 and below 4; hydrochloric, formic and acetic are suitable acids, and as alkalies, milk of lime or dilute caustic soda may be employed; the mechanical treatments comprise comminuting, pounding and pressing, and it is advisable to homogenize the fibrous paste by means of a kneading machine or mixer. The nozzles used for the extrusion are preferably tapered. For obtaining short fibres, the paste is extruded intermittently as by periodically varying the extrusion pressure, or the continuous filaments are collected on intermittently moving belts so that the filaments are broken at the nozzle into short lengths; alternatively, the continuous filaments may be cut or torn into lengths after drying or tanning. The filaments may be twisted together before or during the sizing operation, or after the sized filaments have been rendered sticky or tacky; and the threads may be treated with softeners, wetting agents, mordants, fats, colours &c. Specifications 422,990, [Group IX], and 429,039 are referred to.ALSO:Animal hide material is converted into a highly swollen slippery paste still containing the natural fibres of the hide material by treatment with swelling agents and if desired mechanical treatment. The paste should contain not more than 20 per cent of dry substance, preferably 6-12 per cent. The necessary swelling may be effected by acid or alkaline media, or in an alkaline medium followed by an acid medium; according to the selected swelling media, pH values of over 12 or below 4 should be maintained; hydrochloric, formic and acetic are suitable acids, and as alkalies, milk of lime and dilute caustic soda may be employed. The mechanical treatments comprise comminuting, pounding and pressing; and it is advisable to homogenize the fibrous paste by treatment in a kneaded or mixer.
|
